Braces? Braces? We don't need no stinkin' braces.

#!/usr/bin/perl

# http://perlmonks.org/?node_id=1195568

use strict;
use warnings;
use Data::Dumper;

my %hash = (
            xxx_text10_yyy => 1,
            xxx_text11_yyy => 1,
            mmm_text12_nnn => 1,
            mmm_text13_nnn => 1,
            abc_text6_ghi  => 1,
            abc_text7_ghi  => 1,
            abc_text8_ghi  => 1,
            abc_text9_ghi  => 1
            );

print Dumper(\%hash);

%hash = ( %hash, map(
  /abc_(.*)_ghi/ ? ( $_, "boom_$1" ) : 
  /mmm_(.*)_nnn/ ? ( $_, "doom_$1" ) :
  (), keys %hash ) );

print Dumper(\%hash);
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